I've sort of softened on re-issues. I don't see any evidence that they cause stagnation in the industry. For true stagnation, you can look to the period starting in the late 1980s, when the Korg M1 was a supermassive black hole of ideas for maybe fifteen years. During this time, synths with knobs were revered by players, but not provided by manufacturers. It was baffling disconnect between what musicians (said they) wanted and what the industry made.
So maybe reissues are an over-atonement, or maybe they're purely market-driven. Either way, they're fine by me.
Reissues are fairly common in eurorack modular, too. Usually, they're not made by the original manufacturers, but are responses to patent expiration. Popular targets are Buchla modules, old Polivoks circuits, Moog, of course. I think these are reliably exciting to see, because you can decide where you want to be traditional and where you want to be innovative.
And ultimately, these instruments wind up in a modern context. Despite reissues, music isn't reverting slowly to the 1980s, to my minor chagrin.